Correction of the RF complex reflection coefficient using air line impedance standards

Comparison of two intrinsic efficiency calibration method for low loss waveguide section

“…Furthermore, J.Randa compare the methods of oneport reflective-termination(RT) technique and multiline one-port(ML1P) method [1] . At 2000, Ulrich Stumper find the extended cross-ratio method of correction of the complex reflection coefficient in waveguides [13,14,15] . In this paper, we evaluate the intrinsic efficiency of a U band waveguide standard section with a modified ML1P method and error box method.…”

Optimization of traceable coaxial RF reflection standards with 7-mm-N-connector using genetic algorithms

“…Using the cross-ratio method at quarter wavelengths (QW) (Stumper, 1993) with a 125 mm air line with slotless inner contacts, and comparing the results obtained with this method with the results from measurements using the regular sliding load (s.l.) calibration, only minor deviations of up to 5 · 10 −3 are found at quarter wavelength frequencies.…”

“…It becomes complex for frequencies below 10 MHz. By using the extended cross-ratio method (Stumper, 1993), a worst-case calculation of the expanded uncertainty of the complex reflection coefficient of coaxial 7 mm reference air lines inserted in an ideal 50 coaxial system yields 13, 1 · 10 −2 at 1 MHz, 1, 4 · 10 −2 at 10 MHz, 3, 2 · 10 −3 at 100 MHz, and 3 · 10 −3 at 250 MHz. Alternative methods to determine traceable reflection coefficients in the MHz range should yield uncertainty values not exceeding 3 · 10 −3 .…”

“…At PTB the traceability of RF complex reflection coefficients is achieved by the cross-ratio method (Stumper, 1993) using calculable transmission line impedance standards (Leuchtmann, 2002) i.e. reference coaxial precision air lines without any supporting beads of the center conductor.…”